Tool support



Nov. 24, 1959 QSTE'RTAG EIAL 2,913,996

TOOL SUPPORT Filed March 16, 1955 WMS S rW United States Patent 2,913,996 TOOL SUPPORT Otto Ostertag, Stuttgart-Sillenbuch, and Eugen Stiihle, Magstadt, near Stuttgart, Germany, assignors to Robert Bosch, G.m.b.H., Stuttgart, Germany Application March 16, 1955, Serial No. 494,697 3 Claims. (Cl. 104-14) designed to be connected to the tool at the center of gravity thereof or along the line in which the tool exerts its force, and such supports are even rigid or exert a force against the tool in order to counter-balance the Weight thereof. When such supports are used with elongated tools which engage the ground, such as poweroperated tampers and the like, it is necessary to change the inclination of the tools, and in order to accommodate the support to such changes in inclination it has been neccessary to interrupt the operations and adjust the support or change one support for another support.

It is an object of the present invention to overcome the above drawbacks by providing a support which can carry a tool and which can have its inclination changed during the operation of the tool.

Also, it is an object of the present invention to provide such a support with a means for counter-balancing the weight of the tool at all inclinations of the support so that the operator need only hold and guide the tool and need never support a part of the weight of the tool.

Furthermore, it is an object of the present invention to provide a means for preventing the vibrations of the tool from being transmitted to the interior of the support.

With the above objects in view the present invention mainly consists of a support for a hand-operated, powerdriven tool or the like, this support including a plurality of telescoped members which are adapted to carry the tool and a spring means operatively engaging the members for counterbalancing the weight of the tool at any inclination of the telescoped members, so that the operator need not support the tube.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

Fig. 1 is a side elevational view of the support of the invention shown connected to a diagrammatically illustrated tool which is used together with the support of p the invention; and

Fig. 2 is a sectional elevational view illustrating the details of the support of the invention.

Referring now to the drawings, Fig. l diagrammatically shows an elongated electric hammer 1 which carries at its bottom end a tamping shoe 2 which is adapted to tamp the ground or the like as when a road bed is being prepared for a railroad track, for example. A clamp 3 of any known construction is removably clamped to the tool 1 and carries a pin 4 which extends through a bore formed in an ear which is fixed to and extends from a closure plate 5, so that the tool 1 is in this way tiltably connected to the closure plate 5.

This closure plate 5 is fixed to and closes the top end of the outermost tube 6 of a group of telescoped tubes 6-8, the tube 7 being located within the tube '6 and the tube 8 being located within the tube 7. The bottom open end of the tube 8 is closed by a closure member 9 which is fixed to the tube8 and which has a pointed free end for engaging the floor or ground, as indicated in Fig. 1.

As is shown in Fig. 2, a coil spring 10 is located within the telescoped tubes and has its opposite ends respectively abutting against the closure members 5 and 9. A shaft 11 is fixed to the closure member 5 and extends along the interior of the coilspring 10, this shaft 11 having a length approximately equal to the length of the tube 6. Sleeves 12 and 14 are respectively fixed to the inner faces of tubes 6 and 7 and slidably engage the tubes 7 and 8, respectively, while rings 13 and 15 are respectively fixed to the exterior of the tubes 7 and 8 and slidably engage the inner faces of the tubes 6 and 7, respectively. Thus, these rings and sleeves limit the extent to which the tubes may move out of one another to their fully expanded position and also serve to prevent foreign matter from entering into the interior of the tubes.

The force of the spring 10 is such that when the tubes are expanded it exerts a smaller force than when the tubes are collapsed. When the tubes are fully collapsed Within one another the force of the spring 10 is equal to the weight of the hammer 1. Referring to Fig. 1, it will be seen that the closure member 9 and the shoe 2 engage the ground during operation of the tool. When the operator holds the tool 1 in an almost vertical position with the shoe 2 engaging the ground, almost the entire weight of the tool will be supported by the shoe 2, and at this time the tubes 6- 8 are fully expanded so that the spring 10 exerts only a very light force which is sufiicient to counterbalance the small part of the weight of the tool which is transferred to the support of the invention. As the operator inclines the tool 1 more and more toward a horizontal position, however, it is apparent that a great portion of the weight of the tool will be carried by the support structure shown in Fig. 2. However, during such a change in inclination the tubes move into one another to a greater extent and the spring 10 becomes compressed to a greater extent, since the shoe 2 is maintained at the same elevation in engagement with the ground during tilting of the tool 1. Thus, as the tool 1 approaches a horizontal position the'increased compression of the spring 10 causes it to automatically exert a greater force and counterbalance the greater portion of the weight of the tool 1 which is now transferred to the support. In other words the structure of the invention is so designed that the spring 10 will at all times exert a force tending to expand the tubes which is equal to the force derived from the weight of the tool which tends to collapse the tubes, so that at no time does the operator have to support part of the weight of the tool. When the tool has reached an almost horizontal position, the tubes are fully collapsed and the spring 10 is compressed to the greatest extent to carry substantially the full weight of the tool.

The location of the shaft 11 within the coil spring 10 prevents the coil spring from vibrating so that the coil spring cannot participate in the vibrations of the tool. Furthermore, it will be noted from Fig. 2 that the tube 8 closely surrounds the part of the coil spring 10 located within this tube 8 while the shaft 11 extends through that part of the coil spring which is within the larger tubes 6 and 7. Thus, the shaft 11 guarantees that the spring 10 will not deviate laterally during compression of the spring in the space about the coil spring within the tubes 6 and 7.

Instead of providing the closure member 9 with a pointed end to engage the ground, it is possible to pivotally connect a foot plate to such a closure member.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of supports dilfering from the types described above.

While the invention has been illustrated and described as embodied in supports for hand-operated power-driven tools, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A support arrangement for a hand operated, power driven tool or the like comprising, in combination, a support including a plurality of telescoped tubes, one of said tubes being an outermost tube having an open end located beyond all of the other tubes and one of said tubes being an innermost tube having an open end located beyond all of the other tubes, said tubes being movable between an expanded position and a collapsed position, a pair of closure members respectively fixed to said outermost and innermost tubes at said open ends thereof for closing said open ends, one of said closure members being adapted to engage the ground to support said support for tilting movement between an upright position and a plurality of inclined positions, and a compression spring located within said tubes, having opposite ends engaging said closure members and tending to move said tubes to said expanded position thereof; an elongated tool of a given weight having at one free end thereof means for engaging the ground; and connecting means for pivotally connecting said tool adjacent the other end thereof to said closure member at a distance from said free end of said tool substantially equal to the length of said support in the expanded position of said tubes, said elongated tool being movable with the means thereon engaging the ground from a substantially upright position, in which the weight thereof rests substantially on said means and in which only a small part of its weight is supported by said support so that said compression spring will maintain the tubes of said support in expanded position, to a plurality of inclined positions in which a progressively greater part of the weight of the tool is supported by said support so that the compression spring will be compressed and said support will be moved to the collapsed position, and said compression spring being constructed in a manner so as to counterbalance in all positions of said support the weight component of said tool acting on said support, whereby the weight of said tool is resiliently counterbalanced in all positions of said support.

2. A support arrangement for a hand operated, power driven tool or the like comprising, in combination, a support including a plurality of telescoped tubes, one of said tubes being an outermost tube having an open end located beyond all of the other tubes and one of said tubes being an innermost tube having an open end located beyond all of the other tubes, said tubes being movable between an expanded position and a collapsed position, a pair of closure members respectively fixed to said outermost and innermost tubes at said open ends thereof for closing said open ends, one of said closure members being in the form of a cone adapted to engage with the point thereof the ground to support said support for tilting movement between an upright position and a plurality of inclined positions, and a compression spring located within said tubes, having opposite ends engaging said closure members and tending to move said tubes to said expanded position thereof; an elongated tool of a given weight having at one free end thereof means for engaging the ground; and connecting means for pivotally connecting said tool adjacent the other end thereof to said closure member at a distance from said free end of said tool substantially equal to the length of said support in the expanded position of said tubes, said elongated tool being movable with the means thereon engaging the ground from a substantially upright position, in which the weight thereof rests substantially on said means and in which only a small part of its weight is supported by said support so that said compression spring will maintain the tubes of said support in expanded position, to a plurality of inclined positions in which a progressively greater part of the weight of the tool is supported by said support so that the compression spring will be compressed and said support will be moved to the collapsed position, and said compression spring being constructed in a manner so as to counterbalance in all positions of said support the weight component of said tool acting on said support, whereby the weight of said tool is resiliently counterbalanced in all positions of said support.

3. In combination, an elongated tool means having a free end adapted to engage the ground so that at least part of the weight of said tool means is supported thereon; elongated support means for resiliently counterbalancing the part of the weight of said tool means not supported by the ground engaging end of said tool means, said elongated support means including a plurality of longitudinally shiftable members, spring means operatively engaging said shiftable members for progressively urging said support means between a plurality of contracted positions and a fully expanded position, said spring means having a length substantially equal to the length of said support means and exerting progressively increasing forces in said contracted positions and a minimum force in said expanded position of said support means, and engaging means connected to one end of said elongated support means adapted to engage the ground along a limited area to support said support means for tilting movement between an upright position and a plurality of inclined positions; and connecting means for pivotally connecting the other end of said support means to said elongated tool means at a distance from the ground engaging end of the latter substantially equal to the length of said support means in expanded position, said elongated tool means being progressively movable from a substantially upright position in which the weight thereof rests substantially on the ground engaging end of said tool means and in which only a small part of this weight is supported by said support means in said expanded position, to a plurality of inclined positions in which a progressively greater part of the weight of the tool means is supported by said support means so that said support means will be moved to said contracted position thereof.

References Cited in the file of this patent UNITED STATES PATENTS 13,646 Goodrum Oct. 9, 1855 686,257 Burgh Nov. 12, 1901 1,303,725 Rhine May 13, 1919 1,303,790 Gilman May 13, 1919 1,681,192 McBride Aug. 21, 1929 1,782,660 Meyer Nov. 25, 1930 1,999,844 McElroy Apr. 20, 1935 2,329,932 Nelson Sept. 21, 1943 2,606,050 Morris et al. Aug. 5, 1952 2,733,885 Brown Feb. 7, 1956 FOREIGN PATENTS 26,275 Great Britain of 1906 42,218 Switzerland Mar. 21, 1917 

